An evaluation of blocking probability for three-fold SDMA

Space division multiple access (SDMA) uses the advantage of the smart antenna technology to form a directional antenna pattern in a cellular. By exploiting the directional antenna pattern for users, SDMA can achieve spatial orthogonality among users and channel reuse within a cell. Several studies (Fuhl 1997; Buracchini et al. 1996) have shown the performance improvement of SDMA in a mobile communication environment. This paper extends the two-folding SDMA blocking probability derivation from Galvan-Tejada and Gardiner (1999) and approximately two-folding SDMA approaches from Huang and Doherty (2001). An approximate model is proposed for three-folding SDMA and the corresponding blocking probability is derived. Analytical and simulation results show that three-fold SDMA increases capacity over the traditional cellular system, which demonstrates the effectiveness of SDMA for resource management.